An optical transmitter may emit light that is directed toward an object. For example, in a gesture recognition system, the optical transmitter may transmit near infrared (NIR) light toward a user, and the NIR light may be reflected off the user toward an optical receiver. In this case, the optical receiver may capture information regarding the NIR light, and the information may be used to identify a gesture being performed by the user. For example, a device may use the information to generate a three dimensional representation of the user, and to identify the gesture being performed by the user based on the three dimensional representation.
In another example, information regarding the NIR light may be used to recognize an identity of the user, a characteristic of the user (e.g., a height or a weight), a characteristic of another type of target (e.g., a distance to an object, a size of the object, or a shape of the object), or the like. However, during transmission of the NIR light toward the user and/or during reflection from the user toward the optical receiver, ambient light may interfere with the NIR light. Thus, the optical receiver may be optically coupled to an optical filter, such as a bandpass filter, to filter ambient light and to allow NIR light to pass through toward the optical receiver.